Polyundecaneamide (nylon 11) and polydodecaneamide (nylon 12) obtained from 11-aminoundecanoic acid and 12-aminododecanoic acid (these raw materials are also called .omega.-amino acids) have excellent low temperature impact resistance, chemical resistance, etc., and hence are convenient for many industrial uses.
Nylon 11 or nylon 12 made from an .omega.-amino acid is obtained by suspending particles of a powder of granules of the .omega.-amino acid in water to form a suspension, heating the suspension to evaporate the water and melt the .omega.-amino acid, and polycondensing the obtained melted .omega.-amino acid (British Pat. No. 790,170).
Since this method employs water, a large quantity of heat energy is required to evaporate the water and polymerize the .omega.-amino acid. Therefore, it has been proposed that the .omega.-amino acid is polycondensed directly, without water. However, unlike a batch polycondensation method, a continuous polycondensation method has the problem that the polycondensation cannot be smooth and continuous since the .omega.-amino acid is in the form of particles of a powder or granules, and since the polycondensation reaction takes place immediately after the .omega.-amino acid has been melted.
Accordingly, in order to turn a higher aliphatic .omega.-amino acid into a polymer with a reduced quantity of energy, the appearance of such a method and apparatus has been desired for continuously as well as smoothly polycondensing particles of .omega.-amino acid without suspending them in water. The present invention has been completed in accordance with the above background.